// MD5Checksum.cpp: implementation of the MD5Checksum class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "MD5Checksum.h"
#include <stdio.h>

/* POINTER defines a generic pointer type */
typedef unsigned char *POINTER;

/* UINT2 defines a two byte word */
typedef unsigned short UINT2;

/* UINT4 defines a four byte word */
typedef unsigned long UINT4;

#define PROTO_LIST(list) list 

/* MD5 context. */
typedef struct _MD5_CTX
{
	UINT4 state[4]; /* state (ABCD) */
	UINT4 count[2]; /* number of bits, modulo 2^64 (lsb first) */
	unsigned char buffer[64]; /* input buffer */
} MD5_CTX;

/* Constants for MD5Transform routine.
*/
#define S11 7 
#define S12 12 
#define S13 17 
#define S14 22 
#define S21 5 
#define S22 9 
#define S23 14 
#define S24 20 
#define S31 4 
#define S32 11 
#define S33 16 
#define S34 23 
#define S41 6 
#define S42 10 
#define S43 15 
#define S44 21 

static unsigned char PADDING[64] = {
	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions.
*/
#define F(x, y, z) (((x) & (y)) | ((~x) & (z))) 
#define G(x, y, z) (((x) & (z)) | ((y) & (~z))) 
#define H(x, y, z) ((x) ^ (y) ^ (z)) 
#define I(x, y, z) ((y) ^ ((x) | (~z))) 

/* ROTATE_LEFT rotates x left n bits.
*/
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n)))) 

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation.
*/
#define FF(a, b, c, d, x, s, ac) { \
	(a) += F((b), (c), (d)) + (x)+(UINT4)(ac); \
	(a) = ROTATE_LEFT((a), (s)); \
	(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
	(a) += G((b), (c), (d)) + (x)+(UINT4)(ac); \
		(a) = ROTATE_LEFT((a), (s)); \
		(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
	(a) += H((b), (c), (d)) + (x)+(UINT4)(ac); \
	(a) = ROTATE_LEFT((a), (s)); \
	(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
	(a) += I((b), (c), (d)) + (x)+(UINT4)(ac); \
		(a) = ROTATE_LEFT((a), (s)); \
		(a) += (b); \
}

#define TEST_BLOCK_LEN 1000 
#define TEST_BLOCK_COUNT 1000 

static void MD5Transform PROTO_LIST((UINT4[4], const unsigned char[64]));
static void Encode PROTO_LIST((unsigned char *, UINT4 *, uintptr_t));
static void Decode PROTO_LIST((UINT4 *, const unsigned char *, uintptr_t));
static void MD5_memcpy PROTO_LIST((POINTER, POINTER, uintptr_t));
static void MD5_memset PROTO_LIST((POINTER, intptr_t, uintptr_t));
static void MD5Init PROTO_LIST((MD5_CTX *));
static void MD5Update PROTO_LIST((MD5_CTX *,const unsigned char *, uintptr_t));
static void MD5Final PROTO_LIST((unsigned char[16], MD5_CTX *));
static void MDTimeTrial PROTO_LIST((void));
static void StringAddOne PROTO_LIST((char *));
static void Encode PROTO_LIST((unsigned char *, UINT4 *, uintptr_t));
static void Decode PROTO_LIST((UINT4 *, const unsigned char *, uintptr_t));

/* MD5 initialization. Begins an MD5 operation, writing a new context.
*/
static void MD5Init(MD5_CTX *context)
{
	context->count[0] = context->count[1] = 0;
	/* Load magic initialization constants.
	*/
	context->state[0] = 0x67452301;
	context->state[1] = 0xefcdab89;
	context->state[2] = 0x98badcfe;
	context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest
operation, processing another message block, and updating the
context.
*/
static void MD5Update(
	MD5_CTX *context, /* context */
	const unsigned char *input, /* input block */
	uintptr_t inputLen /* length of input block */
	)
{
	uintptr_t i, index, partLen;

	/* Compute number of bytes mod 64 */
	index = (uintptr_t)((context->count[0] >> 3) & 0x3F);

	/* Update number of bits */
	if ((context->count[0] += ((UINT4)inputLen << 3))
		< ((UINT4)inputLen << 3))
		context->count[1]++;
	context->count[1] += ((UINT4)inputLen >> 29);

	partLen = 64 - index;

	/* Transform as many times as possible.
	*/
	if (inputLen >= partLen) {
		MD5_memcpy
			((POINTER)&context->buffer[index], (POINTER)input, partLen);
		MD5Transform(context->state, context->buffer);

		for (i = partLen; i + 63 < inputLen; i += 64)
			MD5Transform(context->state, &input[i]);

		index = 0;
	}
	else
		i = 0;

	/* Buffer remaining input */
	MD5_memcpy
		((POINTER)&context->buffer[index], (POINTER)&input[i],
		inputLen - i);
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
the message digest and zeroizing the context.
*/
static void MD5Final(
	unsigned char digest[16], /* message digest */
	MD5_CTX *context /* context */
	)
{
	unsigned char bits[8];
	uintptr_t index, padLen;

	/* Save number of bits */
	Encode(bits, context->count, 8);

	/* Pad out to 56 mod 64.
	*/
	index = (uintptr_t)((context->count[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	MD5Update(context, PADDING, padLen);

	/* Append length (before padding) */
	MD5Update(context, bits, 8);

	/* Store state in digest */
	Encode(digest, context->state, 16);

	/* Zeroize sensitive information.
	*/
	MD5_memset((POINTER)context, 0, sizeof(*context));
}

/* MD5 basic transformation. Transforms state based on block.
*/
static void MD5Transform(
	UINT4 state[4],
	const unsigned char block[64]
	)
{
	UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

	Decode(x, block, 64);

	/* Round 1 */
	FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
	FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
	FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
	FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
	FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
	FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
	FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
	FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
	FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
	FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
	FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
	GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
	GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
	GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
	GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
	GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
	GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
	GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
	GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
	GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
	GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
	GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
	GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
	HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
	HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
	HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
	HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
	HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
	HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
	HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
	HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
	HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
	HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */

	/* Round 4 */
	II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
	II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
	II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
	II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
	II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
	II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
	II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
	II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
	II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
	II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */

	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;

	/* Zeroize sensitive information.
	*/
	MD5_memset((POINTER)x, 0, sizeof(x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
a multiple of 4.
*/
static void Encode(
	unsigned char *output,
	UINT4 *input,
	uintptr_t len
	)
{
	uintptr_t i, j;

	for (i = 0, j = 0; j < len; i++, j += 4) {
		output[j] = (unsigned char)(input[i] & 0xff);
		output[j + 1] = (unsigned char)((input[i] >> 8) & 0xff);
		output[j + 2] = (unsigned char)((input[i] >> 16) & 0xff);
		output[j + 3] = (unsigned char)((input[i] >> 24) & 0xff);
	}
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
a multiple of 4.
*/
static void Decode(
	UINT4 *output,
	const unsigned char *input,
	uintptr_t len
	)
{
	uintptr_t i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
		output[i] = ((UINT4)input[j]) | (((UINT4)input[j + 1]) << 8) |
		(((UINT4)input[j + 2]) << 16) | (((UINT4)input[j + 3]) << 24);
}

/* Note: Replace "for loop" with standard memcpy if possible.
*/
static void MD5_memcpy(
	POINTER output,
	POINTER input,
	uintptr_t len
	)
{
	uintptr_t i;

	for (i = 0; i < len; i++)
		output[i] = input[i];
}

/* Note: Replace "for loop" with standard memset if possible.
*/
static void MD5_memset(
	POINTER output,
	intptr_t value,
	uintptr_t len
	)
{
	uintptr_t i;

	for (i = 0; i < len; i++)
		((char *)output)[i] = (char)value;
}

/* Digests a string and prints the result.
*/
void MD5String(const unsigned char *pData, unsigned long dwlen, PTCHAR outString)
{
	MD5_CTX context;
	unsigned char digest[16];
	//TCHAR output1[34];
	intptr_t i;

	MD5Init(&context);
	MD5Update(&context, pData, dwlen);
	MD5Final(digest, &context);

	/*
	for (i = 0; i < 16; i++)
	{
		wsprintf((LPTSTR)&(output1[2 * i]), _T("%02X"), (unsigned char)digest[i]);
		wsprintf((LPTSTR)&(output1[2 * i + 1]), _T("%02X"), (unsigned char)(digest[i] << 4));
	}
	output1[32] = '/0';
	lstrcpy(outString, output1);
	*/
	for (i = 0; i < 16; i++)
		wsprintf((LPTSTR)&(outString[i << 1]), _T("%02X"), (unsigned char)digest[i]);
	return;
}

void MD5String(const unsigned char *pData, unsigned long dwlen, char *outString, intptr_t outLength, bool lowercase)
{
	MD5_CTX context;
	unsigned char digest[16];
	//char output1[34];
	intptr_t i;

	MD5Init(&context);
	MD5Update(&context, pData, dwlen);
	MD5Final(digest, &context);

	/*
	for (i = 0; i < 16; i++)
	{
		sprintf_s(output1 + i * 2, 34 - i * 2, lowercase ? "%02x" : "%02X", (unsigned char)digest[i]);
		sprintf_s(output1 + i * 2 + 1, 34 - i * 2 - 1, lowercase ? "%02x" : "%02X", (unsigned char)(digest[i] << 4));
	}
	output1[32] = 0;
	strcpy_s(outString, outLength, output1);
	*/
	for (i = 0; i < 16; i++)
		sprintf_s(outString + (i << 1), outLength - (i << 1), lowercase ? "%02x" : "%02X", (unsigned char)digest[i]);
	return;
}

void MD5(const unsigned char *pData, unsigned long dwlen, unsigned char *digest)
{
	MD5_CTX context;
	MD5Init(&context);
	MD5Update(&context, pData, dwlen);
	MD5Final(digest, &context);
}

/* get the string add one.
*/
static void StringAddOne(char * orstring)
{
	uintptr_t len;
	intptr_t i, n;

	len = (intptr_t)strlen(orstring);
	n = len - 1;
	for (i = n; i >= 0; i--)
	{
		if (orstring[i] == '9')
		{
			orstring[i] = 'A';
			break;
		}
		else if (orstring[i] == 'Z')
		{
			orstring[i] = 'a';
			break;
		}
		else if (orstring[i] == 'z')
		{
			orstring[i] = '0';
			continue;
		}
		else
			orstring[i] += 1;
		break;
	}
}
